Aquaculture is one of the fastest-growing food sectors, with an annual growth rate said to be in the range of 8-9 percent. Stimulated by increased demand for fish, world fisheries and aquaculture production is projected to reach about 172 million tons in 2021, according to some estimates. The main challenges of the sector include illegal, unreported and unregulated (IUU) fishing, environmental impact, disasters and energy prices. This is especially true in developing countries.
Aquatic animals excrete metabolites (predominantly carbon dioxide, CO2 and ammonia, NH3) and feces into the water. With increasing fish density, these excretions may become toxic and induce pathogen growth. Oxygen demand also increases with density. The importance of water chemistry control thus increases with fish density. Other important aspects of fish culture are freshwater consumption and release of pollutants to the environment.
U.S. Pat. No. 7,527,730 discloses a filtration system which comprises at least one chamber which contains a water inlet, means for distributing water, at least one braker grid, and a water outlet. The braker grid serves the role of providing support to the filtration medium within the chamber, and thus preventing water channeling within the chamber.
PCT Publication No. WO 2003/032718 discloses filtration and aquaculture systems comprising planctomycetes sp. Bacteria that convert ammonia to nitrogen under aerobic conditions, and methods of filtration using Planctomycetes sp.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.